Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Biomedical Sciences

Content Description

1 online resource (ii, xviii, 314 pages) : illustrations (some color)

Dissertation/Thesis Chair

Randall H Morse

Committee Members

Joan M Curcio, Todd A Gray, JoEllen Welsh, Prashanth Rangan


ChIP-seq, Mediator complex, Pre-initiation complex, RNA Polymerase II, TFIID complex, Transcription, RNA polymerases, Genetic transcription, Promoters (Genetics), Yeast

Subject Categories

Genetics | Molecular Biology


The Mediator complex plays a central, highly conserved role in eukaryotic transcription by RNA Polymerase II (Pol II) by stimulating the cooperative assembly of a pre-initiation complex (PIC) and recruitment of Pol II for gene activation. Mediator recruitment has generally been ascribed to sequence-specific activators engaging subunits from the tail module which in turn function to recruit the middle and head for complete assembly at the UAS. Mediator subunits of the middle and head then bridge the enhancer to connect with the PIC at the core promoter. It is reported that Mediator recruitment at the UAS preferentially occurs at SAGA-dependent, TATA-containing genes. Mediator association at many yeast promoters, which are TFIID-dependent and lack consensus TATA sequences, can occur independently of subunits from the tail module triad. Such tail module-independent recruitment could occur via a mechanism that involves interactions with the PIC.